Uncatalyzed four-component synthesis of pyrazolopyranopyrimidine derivatives and their antituberculosis activities

Recent advancements in the multicomponent synthesis of heterocycles integrated with a pyrano[2,3-d]pyrimidine core

“…The Keggin-type catalyst activated oxygen atoms of carbonyl groups for condensation steps to construct pyrazole ring, Knoevenagel condensation of the aldehyde with barbituric acid, and pyran ring cyclization. 107 Keshavarz et al 110 have progressed a green protocol for the synthesis of the previously reported tricyclic systems 32, 104,108,[111][112][113] using a recyclable heterogeneous organicinorganic hybrid durable nano-catalyst "g-Al 2 O 3 @silane-TMG" (Scheme 21). Thus, four-component one-pot reactions of hydrazine, ethyl acetoacetate, (thio)barbituric acid, and aryl aldehydes in water under gently heating (40 C), and catalytic conditions gave the anticipated products 32 in 85-98% yields.…”

“…Keshavarz et al 110 have progressed a green protocol for the synthesis of the previously reported tricyclic systems 32 , 104,108,111–113 using a recyclable heterogeneous organic-inorganic hybrid durable nano-catalyst “γ-Al 2 O 3 @silane-TMG” (Scheme 21). Thus, four-component one-pot reactions of hydrazine, ethyl acetoacetate, (thio)barbituric acid, and aryl aldehydes in water under gently heating (40 °C), and catalytic conditions gave the anticipated products 32 in 85–98% yields.…”

Multiwalled carbon nanotubes/guanidine/Ni (II): A new and effective organometallic catalyst for the green synthesis of pyrazolopyranopyrimidines

“…Obtained products were characterized with melting point and FT-IR, 1 HNMR, and 13 CNMR analyses and were consistent in comparison with authentic samples. [17,21,43,44] 3 | RESULTS AND DISCUSSION…”

MgFe2O4@Tris magnetic nanoparticles: an effective and powerful catalyst for one-pot synthesis of pyrazolopyranopyrimidine and tetrahydrodipyrazolopyridine derivatives

“…Pyrazolopyranopyrimidines are a group of polycyclic-fused heterocyclic compounds, consisting of rings containing pyrimidine, pyran, and pyrazole. Pyrazolopyranopyrimidine derivatives are of great interest because of their broad pharmacological and biological properties and activities as antimicrobial, 17 antituberculosis, 18 anti-inflammatory, 19 analgesic, 20 and anticancer agents. 21 Tetrahydrodipyrazolopyridines are among the most important nitrogen-containing heterocyclic compounds, and they consist of two parts, pyrazole and 1,4-dihydropyridine.…”